Well I had a bad rod bearing in my 5.3l LS1 motor in my 1999 Chevrolet Silverado Z71 so I am going to swap it for the same engine (130,000 miles) that I picked up for $250. I know how to crank a wrench but I am not too technical. I will be explaining the process as I go. If there is someone that knows of a youtube video or another user that has already done this PLEASE post the links.

Last night I got started on the truck, verified the knocking was still indeed there after a fresh oil change. I took the front tires off, set the truck on jack stands high in the air, removed the hood, battery, altenator, serpentine belt, and 2 plates (1 plastic, 1 steel) from the underside of the engine compartment for easy access to the bottom of the motor later.

I unhooked the throttle cables, air intake, drained the oil and started working on removing the main wiring harness (driver side of engine) connections from the top of the motor. I basically unpluigged everything that is connected to the motor from this main harness and labeled some of the stuff to save time later.

Tonight I plan on draining the radiator and removing all the hoses and remaining wireing from the engine block as well as the fan and disconnecting the exhaust. My hope is to start unbolting the motor from the transmission so all I have to do is unbolt the motor mounts and pull the engine.

Here is the question of the day: I see you can buy GM part #12561721 cam which is the same cam they use in the CRATE HO engine. Will there be a noticeable difference if I just replace the cam and is it worth it for the $70? If I decide to do this is there anything else I need to worry about besides simply swapping the cams (I heard the timing will be fine with a basic swap).

 

apparently no one looks at these forums but I will keep updating anyways. Well tonight I picked up the engine hoist (cherry picker) and got it to the garage, assembled, and unloaded the replacement motor. Took a nice long look at the engine on the hoist as to see what I am in for ahead of me. They left all the hoses, plug wires, etc up so I can just compare the 2 engines if I get confused. Drained the radiator, removed the rest of the wiring.

Hopefully tomorrow I can get the fan out, remove the starter (if I need to), remove lower 3 of the 6 bolts holding the motor to the bellhousing. Lower the replacement engine and hook up the hoist to the old motor. I might need to remove my grill but I hope not. That will probably be it.

Question: How the hell do I remove the fuel lines from the motor? There is a thin odd metal clip that I removed but does the hose pop off that fitting? I cannot seem to yank it off the motor right now, how do I remove these things?

PS: Not in as much of a rush since my bad bought a tahoe with the 5.7l, I can borrow this to tow my boat if I need to. I was hoping to get this done Saturday night. That's another good 17hrs at least.

 

Hey bud sorry, I been sick. That fuel line should just come off with a pry tool like flat head screwdriver. It has a o-ring making it tight. As far as cam, here is some info so you can better understand... http://www.ls1tech.com/forums/genera...cam-guide.html

And here is some options... http://www.vincihiperformance.com/ca...s%20truck.html

 

Ruff: Is it true that I need to remove the front grille as well to remove the motor from the engine compartment? If I don't need to do this it would save a lot of time. I measured the opening with the hood off and its like 27" The length of the motor is like 28" will I be able to meneuver it enough with the cherry picker to avoid taking the grill off?

Also it appears I will need to remove the AC compressor. The lower rear bolt is a @$*% to get off cause you can only get a damn open end in there with the frame and what looks to be a frame brace in the way.. I think I might wait to remove this after the engine is loose and jacked up a little bit.

 

Well with just an inch to play with is asking for frustration and problems, especially if your doing it by yourself.

 

Well it's been hot in the Twin Cities and hadn't had much time to work on the truck. Took a 1/2 day off from work and went to town.

Removed:

Fan - (couple of snap tabs to seperate the upper and lower fan cowls, and a couple of bolts air socket friendly)
radiator - (also air socket friendly, and a couple of hoses to disconnect)
fuel lines - (used special 3/8" disconnect tool which was slick)
removed some wiring harness brackets and disconnected all wires off the front and a couple of ground wires grounded to the lower frame.
water pump - (a few stubborn bolts, some air socket friendly some ratchet-style wrench)
ac compressor - (much easier to access once fan and radiator are removed, and peel back the plastic in the passenger fender well by popping the clips out with the skinny flat head, and some open ends get the job done)
Started on the exhaust pipes - I loosened 2 of the 3 with breaking bar socket combo and 3/8" socket with extensions using a spark wire socket of all things but this didnt work on the 3rd nut and I needed to locate my deepwell 15mm socket. Found it but called it quits at this point.
Removed the oil sending unit sensor with a cresent wrench and busted the clip holding the sensor wire on. I think some electrical tape will be fine.

I had to remove all of these components at some point as they did not come on the new motor.

You will need a nice long skinny flat head screwdriver for all of the wiring harness clips and other various clips you need to remove. A cresent wrench, some breaking bars for your 1/4, 3/8" drive and mostly 10, 12, 15, 1/2" 3/4" sockets and open ends, I like the wratchet wrenches and use the air wrench whenever possible.

I returned the bad rebuilt altenator to o'reilly's and they gave me a brand new one. I also picked up a serpentine belt and compressor belt, and bosch platinum spark plugs as I pulled one from the new engine and it was black on the 4 conductors.

Tomorrow I will remove the starter, remove lower bell housing bolts, finish removing 4 exhaust bolts, then remove upper bell housing bolts, hook the cherry picker up to the motor and work on the motor mounts.

All the hoses and wires are just pushed off to the sides of the engine so the motor should have plenty of room to come out of the hood opening.

In the meantime here are some pics of my new ride:

'95 2 door 1500 4x4 Tahoe LT with the 5.7l 350 in it. I added the deflector, smoker vents, and picked up a new rear bumper from a guy (the other one is in bad shape). I tried to swap the bumpers but the bolts seem to be a pain in the *** to get to.



'99 Silverado 1500 LS

 

missed a few bell housing bolts and bolts holding some ground wires on. Those 15mm transmission bolts can be tricky on the upper side of the motor and crammed back by the firewall. It takes patience but you can get them with an open end and eventually just hand loosening them with some solid finger control.

Got all 6 bolts removed from both motor mounts. Than I pried the transmission away from the motor a few inches, roated the flyweel so the torque converter bolt was in a position where I could get a 8mm alan wrench in there with a small breaking bar. I had my helper use a 1" socket on the front of the motor with a breaking bar as I held the alan w/breaking bar in place and it broke the nut loose. Rotated the fly wheel 2 more times so the nuts were accessible using this method.

I pried the torque converter back into the transmission bell housing, while hoisting the engine up with the engine hoist and it came free. I had to drop the motor down a bit and readjust my grab point to straighten the motor out when it pulled through the engine opening using pry bars when needed and rolling the truck backward as well.

My next steps are to prep the new engine as it sits on the engine stand. Swap the spark plugs, inspect the wires, spray some cleaner on the plugs, maybe hit up the intake manifold with some sort of lubricant. Remove the main motor wiring harness from the new motor (the mechanic just cut wires and hoses during removal from salvage vehicle) making note of what colorod wires and grounds connect where on the motor. I might take some pics of this for reference.

I need to change my pitman arm which will be much easier now that the motor is out. I will do this prior to dropping the new motor in. Then It's just reverse the steps for installation of the replacement 5.3l.

I am going to throw the grease gun on any zerk fittings I see before I put the new motor in and clean up the engine compartment a bit. If there are any gaskets I will replace them with new.

I will update you as I do the installation and leave my tips of things to watch out for and avoid during the installation process. Lots to do here's my list:

1. Line up motor with transmission torque converter, bolt on torque converter (8mm alan wrench with someone holding bell housing; can use 1" socket on front of motor with breaking bar to hold flywheel).

2. Bolt transmission bellhousing to rear motor, 8 15mm bolts a few which grounds will connect to. Connect any remaining bolts grounds to upper and lower of motor.

3. Bolt down motor mount brackets (3 bolts per mount on either side of the motor)

4. Bolt exhaust back onto exhaust manifolds (3 15mm nuts per manifold)

5. Bolt starter back on and connect any associated wires.

6. bolt a/c compressor back on and connect any associated wires and hoses.

6a. route the compressor belt when connecting the a/c compressor (I replaced mine)
7. bolt water pump back on connecting any associated wires and hoses

8. connect any wires to the top of the motor from the main wiring harness and any hoses prior to connecting the air system.

9. connect all fuel lines and throttle cables

10. connect the altenator and any wires associated with it routing the serpentine belt around all components, altenator, water pump, power steering, idler, tensioner, etc.(I replaced mine)

10a. change the oil, flush the tranny, fill up the tranny fluid and flush and fill the cooling system.

11. Connect the battery and fire her up and see if any warning lights come on.

12. If all is well I will put the air intake back onto the intake manifold and double check all the wires and hoses are routed properly and all associated harnesses and brackets are in place and clipped properly.

13. Put the front plastic fender well covers back in using there black snaps.

14. Put hood back onto brackets and let er buck!

 

Good deal man!! And the anxiety gets stronger as she will soon roar!

 

Hey dude, great post. I'm just about to pull the 5.3 on my 2000 and swap it with another as well. Your step by step is very reassuring to know what I have ahead of me. Did it go back in well, and did it start and run with no issues?

 

I admire guys that can do this sort of thing. Even though I will never do anything like this, It was real good of you to put this together for the other guys on this board.

THANKS DUDE!